The Earth rotates once on its axis about every 24 hours. As the Earth rotates, observers on Earth see the Sun moving across the sky from east to west with the beginning of each new day. We often say t...The Earth rotates once on its axis about every 24 hours. As the Earth rotates, observers on Earth see the Sun moving across the sky from east to west with the beginning of each new day. We often say that the Sun is “rising” or “setting,” but it is the Earth’s rotation that gives us the perception of the Sun rising or setting over the horizon. As Earth turns, the Moon and stars also change position in our sky.
